Selectively disengagable sealing system

ABSTRACT

A seal assembly including a first tubular having a sealing surface and a seal element run with the first tubular and displaced from the surface. The seal element initially has a radial dimension that forms a radially innermost or outermost sealing dimension of the first tubular for enabling the first tubular to be sealed with a second tubular radially disposed with the first tubular. A mechanism is included that is triggerable for reconfiguring the radial dimension of the seal element. The sealing surface of the first tubular operative forms the radially innermost or outermost sealing dimension of the first tubular when the radial dimension of the seal element has been reconfigured for enabling the sealing surface of the first tubular to receive a second seal element. A method of sealing tubulars is also disclosed.

BACKGROUND

Seals are used ubiquitously in the downhole drilling and completionsindustry. Commonly seals are disposed on the outer surface of a radiallyinwardly disposed tubular. However, so-called inverted seals have gainedfavor for use in gravel pack operations as they enable the use of aslick outer diameter (OD) crossover tool. These slick OD crossover toolshave several advantages over prior crossover tools, which includeshoulders and seal elements bonded thereon that can become stuck onother components during run-in and pull out of the tool and adjacenttools. However, the inverted seals often become damaged during gravelpack operations and are unreliable during production after the crossovertool has been removed. Accordingly, the industry always well receivesadvances in seal technology in general and inverted seal technologyspecifically.

BRIEF DESCRIPTION

A seal assembly including a first tubular having a sealing surface; aseal element run with the first tubular and displaced from the surface,the seal element initially having a radial dimension that forms aradially innermost or outermost sealing dimension of the first tubularfor enabling the first tubular to be sealed with a second tubularradially disposed with the first tubular; and a mechanism triggerablefor reconfiguring the radial dimension of the seal element, the sealingsurface of the first tubular operatively forming the radially innermostor outermost sealing dimension of the first tubular when the radialdimension of the seal element has been reconfigured for enabling thesealing surface of the first tubular to receive a second seal element.

A method of selectively sealing tubulars including sealing a sealelement of a first tubular with a second tubular; performing a downholeoperation; disabling the seal element by changing a radial dimension ofthe seal element so that it is no longer capable of sealing with thesecond tubular; pulling out the second tubular; and miming in a thirdtubular having a second seal element thereon operatively arranged forsealing against a surface of the first tubular.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way.With reference to the accompanying drawings, like elements are numberedalike:

FIG. 1 is a quarter-sectional view of an assembly having a seal elementengaged between two tubulars;

FIG. 2 is a quarter-sectional view of the assembly of FIG. 1 where theseal element is disabled or deactivated from sealing the tubulars;

FIG. 3 is a quarter-sectional view of an assembly including a sealelement engaged between two tubulars;

FIG. 4 is a quarter-sectional view of the assembly of FIG. 1 where axialmovement of a sleeve has disabled or deactivated the seal element fromsealing the tubulars;

FIG. 5 is a quarter-sectional view of an assembly including a sealelement engagable between two tubulars;

FIG. 6 is a quarter-sectional view of the assembly of FIG. 5 where axialmovement of the seal element has disabled or deactivated the sealelement from sealing between tubulars;

FIG. 7 is a quarter-sectional view of an assembly including a sealelement engagable between two tubulars;

FIG. 8 is a quarter-sectional view of the assembly of FIG. 7 where axialmovement of a piston has disabled or deactivated the seal element fromsealing between tubulars;

FIG. 9 is a quarter-sectional view of an assembly including a sealelement engagable between two tubulars; and

FIG. 10 is a quarter-sectional view of the assembly of FIG. 9 whereremoval of a support has disabled or deactivated the seal element fromsealing between tubulars.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosedapparatus and method are presented herein by way of exemplification andnot limitation with reference to the Figures.

Referring now to the embodiment of FIGS. 1 and 2, a selectivelydisengagable or deactivatable seal assembly 10 is shown having a sealelement 12. The seal element 12 is disposed with a first tubular 14 inorder to form a sealed engagement with a second tubular 16. The tubular14 is positionable radially outwardly of the tubular 16 or vice-versa.In one embodiment the seal element 12 is an inverted seal, the firsttubular 14 is part of an outer tubular string, and the second tubular 16is a crossover tool housed within the tubular 14 for performing afracturing and/or gravel pack operation. Of course, the tubulars 14 and16 could be other tubulars arranged differently and used for otherpurposes.

The assembly 10 is arranged with a mechanism for enabling the sealelement 12 to selectively disengage from its sealed engagement with oneor both of the tubulars 14 and 16. Various embodiments of mechanismswill be described below with respect to FIGS. 3-10, but it is now notedthat mechanism is generally defined to mean any property, device,assembly, system, parameter, tool, etc., or combinations of theforegoing, which enables the seal element 12 to selectively disengage,deactivate, or disable (these terms used interchangeably herein) thesealing ability of the seal element 12. As the mechanism can take avariety of forms, it may generally be referred to herein that themechanism is “triggered”, although other terms such as actuated,activated, launched, deployed, initiated, etc. may interchangeably beused to designate that some action is being performed related to themechanism for disengaging the seal.

FIGS. 1 and 2 schematically illustrate the seal element 12 beingdisengaged. Initially, the seal element 12 extends radially from thetubular 14 a distance xl such that a radial dimension of the sealelement 12 effectively defines a radially innermost or outermostdimension for the tubular 14, referred to collectively as the “radialsealing dimension” for ease in discussion. That is, in some embodiments,the radial sealing dimension is an inner diameter or an outer diameter.As the seal element 12 forms the radial sealing dimension, e.g., theseal element 12 radially protrudes from the tubular 14, the seal element12 is arranged to form a sealed engagement with the tubular 16, as shownin FIG. 1. As a result of the mechanism being triggered (again, variousembodiments described in more detail below with respect to FIGS. 3-10)the seal element 12 is changed in radial dimension, namely, moved adistance x2 from a surface 18 of the tubular 14. Thus, after triggeringthe mechanism, the surface 18 (or some other surface of the tubular 14)then defines the radial sealing dimension for the tubular 14, i.e., theradially innermost (or outermost) dimension. For example, the surface 18could be formed as a seal bore for receiving a conventional style sealelement run-in on an isolation string after the tubular 16, e.g., acrossover tool, is pulled out. For example, the distance x2 could begreater than or equal to zero. In some embodiments, the seal element 12or portions thereof may extend radially beyond the tubular 14 to somerelatively small or insignificant degree, but nevertheless theengagement with the tubular 16 is disabled and the surface 18 is usedfor resealing the tubular 14.

As noted above, one potential embodiment for use of the assembly 10 andothers described herein is for sealing against a crossover tool withinverted seals during a gravel pack operation. After the operations arecompleted at each desired zone and the crossover tool is no longerneeded, the crossover tool can be pulled out of the hole and theinverted seals disengaged or deactivated as schematically describedabove. After deactivation or disengagement, the inverted seals no longerform the radial sealing dimension, i.e., the innermost diameter, of theouter tubular string. Thus, the inverted seals are changed in radialdimension, e.g., moved radially, so that a typical isolation assemblycan be run-in with production tubing and sealed into seal bores or thelike in the outer tubular string. This avoids the disadvantages ofinverted seals, which are often damaged during gravel pack operationsand inherently unreliable thereafter. Of course, other seal elements,including non-inverted seals could be similarly deactivated in anydesired system, although multi and single zone completions are primecandidates for the currently described assemblies.

One embodiment is shown in FIGS. 3 and 4, in which an assembly 20 isshown between an engaged and a disengaged state, respectively. Theassembly 20 resembles the assembly 10 in basic concept, i.e., having aseal element 22 that is arranged for selectively disengaging from sealedengagement between a first tubular 24 and a second tubular 26. Similarto the assembly 10, the tubulars 24 could be positioned radiallyoutwardly of the tubular 26 or vice-versa. The tubulars 24 and 26 couldrespectively be an outer tubular string and a crossover tool, etc.Multiple ones of the assembly 20 could be included along the length ofthe tubular string 24 in order to, for example, perform a multi-zonefracturing operation.

In the assembly 20, for example, the seal element 22 is held by ahousing that comprises a set of rings 28 a and 28 b. Both of the rings28 a and 28 b are secured or locked to the tubular 24. For example, inthe embodiment of FIGS. 3 and 4, a threaded connection 30 and aconnector 32 are utilized for respectively securing the rings 28 a and28 b to the tubular 24, although other means of connection areappreciable by one of ordinary skill in the art.

The connector 32 is located in a slot 34 of a sleeve 36 for enabling thesleeve 36 to move axially with respect to the tubular 24. The sealelement 22 is radially deformed (either compressed or swaged outward,depending on the relative radial orientation of the tubulars 24 and 26)into place by the sleeve 36. When radially deformed, the seal element 22forms a sealed engagement between the tubulars 24 and 26. Upon axialmovement of the sleeve 36, a narrowed portion 38 of the sleeve 36 isaligned with the seal element 22, enabling the seal element 22 to atleast partially return to an orientation in which it is not deformed.That is, the seal element 22 could spring radially outward or inwardtoward its rest or neutral configuration. As shown in FIG. 4, whenaligned with the narrowed end 38 the seal element 22 changes in radialdimension so that it no longer forms the radial sealing dimension forthe tubular 24. Instead, the radial sealing dimension is formed by asurface of the rings 28 a and 28 b (or some other surface connected tothe tubular 24). In this way, the sleeve 36 with the narrowed end 38acts as a mechanism that can be triggered for disengagement of the sealelement 22.

The sleeve 36 has, for example, a profile 40 for engaging with acomplementarily profiled shifting tool in order to move the sleeve 36,although it is to be recognized that any other method of shifting thesleeve 36 could be utilized. In embodiments in which an isolation stringis run-in after deactivation of the seals, such a shifting tool could beincluded at the leading end of the isolation string, and one or more ofthe assemblies 20 deactivated by, for example, setting weight down onthe sleeve 36 to engage the shifting tool with the profile 40, pullingup on the isolation string to shift the sleeve 36, running the isolationstring to another sleeve, etc.

It is to be appreciated that modifications to any of the assembliesdescribed herein are possible. For example, in an embodiment similar tothat of the assembly 20 the seal element is movable and the sleeve isstationary. That is, for example, with reference to the numberedcomponents of the assembly 20, the sleeve 36 could be secured, lockedto, or formed with the tubular 24 and the seal element 22 slideabletherein in order to align the seal element 22 with the narrowed portion38 of the sleeve 36.

In some embodiments, such as shown in FIGS. 3-4, axial actuation of acomponent, e.g. a sleeve or the seal element itself, disables the sealelement. In other embodiments, rotational movement, could result in aradial change, e.g., the mechanism including or resembling a cam,four-bar linkage, camera aperture, etc. The seal element is disabled inother embodiments by removing the seal element. In some of theseembodiments, the seal element is removable via physical means, such as acutter, blade, mill, drill, etc. that is hydraulically, mechanically,gravitationally, electrically, etc. actuated for removing a portion ofthe seal element by cutting, shearing, etc. In some embodiments, theseal element (or a ring, c-ring, or other member or members disposedtherein or secured thereto) is at least partially plastically deformableand a wedge or other component axially runnable for radially deformingor swaging the seal element. In other embodiments, the seal element isremoved by spotting or delivering a fluid, such as an acid, a solvent,etc. to the seal element in order to degrade, disintegrate, dissolve,corrode, weaken, destroy, or otherwise remove the seal element or aportion thereof (collectively, “degrade”). Similarly, a change intemperature, pressure, or some other downhole condition or parametercould degrade, change the dimensions of, or otherwise trigger themechanism for disabling the seal element. In view of these embodiments,it is clear that the term “mechanism” is used in its broadest sense, asthe mechanism or components thereof may range from physical tools, e.g.,a mill or blade, to the seal element itself, to a property of the sealelement, e.g., dissolvability in the presence of the proper fluid.

Axial movement, e.g., of a tool, device, the seal element, etc. could beused for triggering mechanisms in various other embodiments. Forexample, seal elements could be included on or bonded to a barrel slipassembly, with axial movement between the interlocking jaws of thebarrel slips resulting in a change in the radial positioning of the sealelements. For example, a barrel slip assembly is disclosed in U.S. Pat.No. 7,367,397 (Clemens et al.), which patent is hereby incorporated inits entirety. By placing, for example, seal elements at the innersurface of the “slip body 188” of Clemens et al., the seal elementscould be selectively disengaged or disabled by moving the “annular wedgeassemblies 196, 198” together and apart.

In other embodiments, axial movement enables an axially pre-compressedor axially pre-stretched or tensioned seal element to return to its restposition. For example, similar to a compression-set packer, the sealelement could be compressed between two components, e.g., by a hydraulicpressure, set down weight, etc. In another such embodiment, shown inFIGS. 5 and 6, an assembly 42 includes a deformable body 44 having sealelements 46 thereon. By axially compressing and/or tensioning the body44 between two components and/or enabling the ring 44 to return to itsrest or neutral position after ceasing the compression/tension, theradial dimension of the seal elements 46 can be set.

Another such embodiment utilizing compression/tension of the sealelement is shown in FIGS. 7 and 8, namely, an assembly 48. The assembly48 includes a seal element 50. According to the embodiment of FIG. 7,the seal element 50 is initially axially compressed between a portion orcomponent of a tubular 52 and a piston 54 for forcing the seal element50 to compress axially and bulge radially. The piston 54 could take theform, e.g., of a ring. The piston 54 is initially held in place by arelease member, shown in the form of a shear screw or pin 56, but whichcould take other forms, such as collet fingers, a shear ring, etc. Thepiston 54 is disposed between a pair of chambers 58 and 60. In oneembodiment, the chamber 60 is at atmospheric or some relatively lowpressure. Thus, upon pressurizing the chamber 58 to a predeterminedamount, the release member will release the piston 54, e.g., the screws56 will shear, moving the piston 54 axially and enabling the previouscompressed seal element 50 to return to its rest position. In a relatedembodiment, the shear screws could be removed and the seal element 50compressed by maintaining a high pressure in the chamber 60 and the sealelement released by bleeding off the pressure in the chamber 60. Ofcourse, other mechanisms could be employed that compress or tension sealelements in other ways.

An assembly 62 is another embodiment shown in FIGS. 9 and 10. In theembodiment of the assembly 62, a seal element 64 is included with atubular 66 as being radially compressible or expandable and/or having aresilient member 68. For example, the member 68 could be a c-ring orother resilient or spring-like member that naturally springs, snaps, orotherwise returns back to its neutral position after being radiallydeformed. The seal element 64 in this embodiment is initially supportedby a support member 70. In some embodiments, a secondary seal element 72is included to seal the support member 70 to the tubular 66. The supportmember 70 could be removed in any desired manner in order to enable theseal element 64 and/or the member 68 to radially reposition the sealelement 64 for disabling or disengaging the seal member 64.

In one embodiment the support member 70 is a frangible or breakablematerial, e.g., tempered glass, that is hit, punched, rammed, orotherwise struck or met by a force in order to shatter or break thesupport member. For example, a piston, pin, rod, finger, spike, etc.could be driven into the support member 68 using means such ashydraulics, pneumatics, string weight, etc. Similarly, a largecompressive force could be increasingly applied over a relatively largesurface area to crack or shatter the member 68.

In another embodiment, the support member 70 is made from controlledelectrolytic metallic materials or some other material that can bedegraded, dissolved, disintegrated, corroded, weakened, etc.(collectively, “degraded”) by exposure to a predetermined fluid.Examples of suitable materials and their methods of manufacture aregiven in U.S. Patent Publication No. 2011/0135953 (Xu, et al.), whichPatent Publication is hereby incorporated by reference in its entirety.Suitable materials are also available from Baker Hughes Incorporatedunder the name IN-TALLIC®. Other materials include magnesium, aluminum,etc. that are removable by exposure to acid, etc. The support member 70could be at least partially hollow, perforated, weakened, etc. to aid inits removal.

Of course, any combination of elements from the above describedembodiments, or substitutes, equivalents, analogs, etc. thereof ortherefor are also within the scope of the current invention. In thisway, triggering of some mechanism can be used to reconfigure the radialdimension of the seal element for selectively disabling or deactivatingits seal sealing capability. Further, the tubular including the sealelement can include a seal bore or other surface, e.g., the surface 18in FIG. 1, for receiving a new seal element from another tubular suchthat additional operations requiring isolation, e.g., production, can beperformed.

While the invention has been described with reference to an exemplaryembodiment or embodiments, it will be understood by those skilled in theart that various changes may be made and equivalents may be substitutedfor elements thereof without departing from the scope of the invention.In addition, many modifications may be made to adapt a particularsituation or material to the teachings of the invention withoutdeparting from the essential scope thereof. Therefore, it is intendedthat the invention not be limited to the particular embodiment disclosedas the best mode contemplated for carrying out this invention, but thatthe invention will include all embodiments falling within the scope ofthe claims. Also, in the drawings and the description, there have beendisclosed exemplary embodiments of the invention and, although specificterms may have been employed, they are unless otherwise stated used in ageneric and descriptive sense only and not for purposes of limitation,the scope of the invention therefore not being so limited. Moreover, theuse of the terms first, second, etc. do not denote any order orimportance, but rather the terms first, second, etc. are used todistinguish one element from another. Furthermore, the use of the termsa, an, etc. do not denote a limitation of quantity, but rather denotethe presence of at least one of the referenced item.

What is claimed is:
 1. A seal assembly comprising: a first tubularhaving a sealing surface; a seal element run with the first tubular anddisplaced from the surface, the seal element initially having a radialdimension that forms a radially innermost or outermost sealing dimensionof the first tubular for enabling the first tubular to be sealed with asecond tubular radially disposed with the first tubular; and a mechanismtriggerable for reconfiguring the radial dimension of the seal element,the sealing surface of the first tubular operatively forming theradially innermost or outermost sealing dimension of the first tubularwhen the radial dimension of the seal element has been reconfigured forenabling the sealing surface of the first tubular to receive a secondseal element.
 2. The assembly of claim 1, wherein the first tubular isradially outwardly disposed with respect to the second tubular and theseal element is an inverted seal element.
 3. The assembly of claim 1,wherein the second tubular has a slick diameter engagable by the sealelement before triggering the mechanism.
 4. The assembly of claim 3,wherein the second tubular is a crossover tool.
 5. The assembly of claim1, wherein triggering the mechanism removes at least a portion of theseal element.
 6. The assembly of claim 5, wherein the mechanismcomprises a cutter, blade, mill, drill, grinder, or combinationsincluding at least one of the foregoing.
 7. The assembly of claim 5,wherein the mechanism is a property of the seal element to degrade uponexposure to a fluid and is triggered upon exposure of the seal elementto the fluid.
 8. The assembly of claim 1, wherein the mechanism istriggered by axial movement.
 9. The assembly of claim 8, wherein themechanism comprises a component mounted with the first tubular having aradially narrowed portion for receiving the seal element therein whenaxially aligned therewith.
 10. The assembly of claim 9, wherein thecomponent is a sleeve slidably mounted with respect to the firsttubular.
 11. The assembly of claim 9, wherein the seal element isslidably mounted with respect to the first tubular.
 12. The assembly ofclaim 8, wherein the seal element is axially compressed and released forchanging the radial dimension of the seal element.
 13. The assembly ofclaim 12, wherein the mechanism includes a piston that enables axialcompression and release of the seal element.
 14. The assembly of claim13, wherein the piston is triggerable by pressurizing one of twochambers located on opposite sides of the piston.
 15. The assembly ofclaim 8, wherein the seal element is disposed on a deformable body thatis axially compressed and released for changing the radial dimension ofthe seal element.
 16. The assembly of claim 8, wherein the seal elementis radially swaged.
 17. The assembly of claim 1, wherein the mechanismcomprises a temporary support for initially setting the radial dimensionof the seal element as the radially innermost or outermost sealingdimension for the first tubular and triggering the mechanism involvesremoving the temporary support.
 18. The assembly of claim 17, whereinthe temporary support is frangible and triggering the mechanism involvesbreaking the temporary support.
 19. The assembly of claim 17, whereinthe temporary support is degradable upon exposure to a fluid andtriggering the mechanism involves exposing the temporary support to thefluid.
 20. The assembly of claim 17, wherein the seal element is securedto a resilient element for changing the radial dimension of the sealelement after the temporary support has been removed.
 21. The assemblyof claim 1, further comprising a third tubular that is runnable withrespect to the first tubular after the second tubular is pulled out, thethird tubular having the second seal element thereon.
 22. A method ofselectively sealing tubulars comprising: sealing a seal element of afirst tubular with a second tubular; performing a downhole operation;disabling the seal element by changing a radial dimension of the sealelement so that it is no longer capable of sealing with the secondtubular; pulling out the second tubular; and running in a third tubularhaving a second seal element thereon operatively arranged for sealingagainst a surface of the first tubular.